Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Mechanisms of Disease > Lecture 8.1: Carcinogenesis- Why and How Neoplasms Occur > Flashcards

Lecture 8.1: Carcinogenesis- Why and How Neoplasms Occur Flashcards

1
Q

What is a ‘Neoplasm’?

A

A neoplasm is a newly formed collection of cells resulting from abnormal cellular proliferation that persists after the initial stimulus is removed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the most common benign tumours in women of childbearing age?

A
  • Uterine Fibrosis
  • The development of fibroids increases with age
  • Present in 80-90% of all women by age 50 years
  • Cause pain, excessive menstrual bleeding or infertility
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a Meningioma?

A
  • Most frequently reported primary CNS tumours
  • Approx. 36% of all CNS tumours
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In what form do most carcinogens enter the body?

A

Most carcinogens enter the body as procarcinogens, which are then converted to carcinogens by cellular machinery

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What is Benzopyrene?

A

It is a procarcinogen and is one of the main carcinogenic agents in cigarette smoke

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How does Benzopyrene cause mutations?

A
  • It must first be oxidized by cytochrome P4501A1
  • Further modified by other enzymes to form benzopyrene diol epoxide
  • This binds covalently to DNA, to form an adduct where it causes mutations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

How can radiation damage DNA directly?

A

Misrepairs by DNA repair proteins allow the mutation/chromosomal rearrangement to persist

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

How can radiation damage DNA indirectly? (2)

A

1) Generating free radicals

2) Producing secretable soluble factors that can affect
distal nonirradiated cells

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Examples of Carcinogens (7)

A
  • Asbestos
  • Aromatic amines e.g. 2-naphthylamine
  • Solvents
  • Benzene
  • Polycyclic aromatic hydrocarbons (PAHs)
  • Ionising Radiation
  • Pesticides
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 4 Steps of Carcinogenesis?

A
  • Tumor Initiation
  • Tumor Promotion
  • Malignant Conversion
  • Tumor Progression
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

DNA Damage Responses

A
  • Checkpoint Activation in Cell Cycle
  • DNA Repair (NHEJ,MMR,NER,Direct Reversal…etc)
  • Apoptosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is a Latency Period in Carcinogenesis?

A

There is often a long interval (latency period) between exposure to a carcinogen and clinically-detectable neoplasia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What are Papillomas?

A
  • They are are pre-malignant (benign) tumours
  • These can progress to an invasive, malignant
    carcinoma
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Initiators and Promoters

A

Animal tests have shown that chemical carcinogens, called initiators, must be given first, followed by a second class of carcinogens called promoters

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Sporadic Mutations

A
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Germline Mutations

A
17
Q

What is a Retinoblastoma? How many sporadic vs germline?

A
  • A type of eye cancer that usually develops in early childhood (usually before the age of 6)
  • Affects about 1 in every 15,000 children
  • Approximately 60% of cases are sporadic (no family history)
  • Approximately 40% = family history (inherited)
18
Q

What is the Mechanism of Retinoblastoma Formation?

A
  • Mechanism involves loss of the retinoblastoma protein RB
  • The prototypic tumour suppressor gene
  • Slide 29 for more specifics
19
Q

Alfred Knudson’s ‘Two-Hit’ Hypothesis (1971)

A

“In the dominantly inherited form of the disease, one mutation is inherited via the germ line and the second occurs in somatic cells. In the nonhereditary form, both mutations occur in somatic cells.”

20
Q

What is a Haploinsufficiency?

A

Occurs when one copy of a gene is inactivated or deleted and the remaining functional copy of the gene is not adequate to produce the needed gene product to preserve normal function

21
Q

Xeroderma Pigmentosum (XP)

A

• It is an autosomal recessive disorder
• Due to mutations in one of 7 genes that affect DNA nucleotide
excision repair (NER)
• These patients are very sensitive to UV damage
• They develop skin cancer at a young age

22
Q

What is The Ames Test?

A

Exposure of auxotrophic his- strains of Salmonella typhimurium to potential mutagens

23
Q

What Cancer does Ulcerative Colitis increase the Risk of?

A

Colorectal Cancer

24
Q

What Cancer does Liver Cirrhosis increase the Risk of?

A

Liver Cancer

25
Q

What Cancer does Hashimoto’s Thyroiditis increase the Risk of?

A

Thyroid Cancer

26
Q

What Cancer does Chronic Atrophic Gastritis increase the Risk of?

A

Stomach Cancer

Mechanisms of Disease (11 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions